Jack-in-the-pulpit is a great choice for native-plant shade gardens in the eastern United States. It is one of the more unusual native plants that you can grow and very low-maintenance. Jack-in-the-pulpit is a plant that fascinates children and the young at heart, a plant not difficult to picture in a fairyland setting.
- Botanical Name: Arisaema triphyllum
- Common Name: Jack-in-the-pulpit, Indian turnip, wake robin
- Plant Type: Herbaceous; grows from a corm
- Mature Size: 1 to 2 feet tall, with a similar spread
- Sun Exposure: Partial shade to full shade
- Soil Type: Moist, humusy
- Soil pH: Acidic
- Bloom Time: April to May
- Flower Color: Greenish-purple
- Hardiness Zones: 4 to 9
- Native Area: Eastern North America
How to Grow Jack-in-the-Pulpit
Jack-in-the-pulpit needs shade, an adequate water supply, and nutrients. Once these three elements are provided, the plant is not a lot of work to grow.
To plant, make a 6-inch hole in the ground in fall and drop in the corm, as you would for Crocus, for example. Once the plants have come up in spring and put on some size, shovel 2 to 3 inches of mulch around them in order to conserve moisture. Slug pests like to eat this wild plant, so be sure to practice slug control, as you would for another slug magnet of the shade garden: Hosta.
Some shade is an absolute must. The plant performs well even in deep shade.
These wildflowers do not demand the superb drainage that many plants do, making them an option for boggy soils. The idea is to mimic the native habitat, which is damp, acidic areas of the forest rich in organic matter.
An evenly moist soil is another must for growing Jack-in-the-pulpit.
Fertilizing with compost is sufficient in many cases. But use a fertilizer containing ammonium-N if your soil pH is not acidic enough.
Origin of the Common Name, Best Features
Although Jack-in-the-pulpit plants flower in spring, it is primarily the spathe, a hooded, cup-like growth, that folks care about. This is the "pulpit" from which "Jack" (technically, the "spadix," which takes the form of an erect spike) preaches. The actual flowers are contained on the spadix, but they are not showy; it is the spathe that you notice from a distance in spring, especially when it is striped and/or tinged with purple. Three subspecies exist, and there can be quite a bit of variation in coloration. The top of the spathe is a lip that curls over the spadix as if forming a roof.
By fall, some mature plants will also offer a cluster of showy red berries. They become more visible after the spathe withers away. The berries shine brightly and will add considerable luster to your shade garden late in the growing season.
The three-part compound leaf of Jack-in-the-pulpit may remind some of poison ivy (Toxicodendron radicans) at certain stages of the latter's growth (remember, "leaflets three, let it be"). The leaf structure also resembles that of Trillium, which shares Jack-in-the-pulpit's native habitat, as well as the nickname, "wake robin."
Jack-in-the-pulpits are poisonous plants, the corms (if eaten raw) being considered especially toxic. Native Americans cooked the corms after soaking and drying them, as preparation for both medicinal and culinary uses (thus the common name, "Indian turnip"). But only experts should try this.
Another drawback in growing this plant is that it often goes dormant in summer (especially when it is young), leaving a gap in your garden.
Uses in Landscaping
Grow Jack-in-the-pulpit plants in shade gardens and/or woodland gardens. Jack-in-the-pulpit plants look good when surrounded by a mass of low-growing ground covers such as impatient Lucy (Impatiens walleriana). In fact, when Jack-in-the-pulpit plants go dormant and leave a hole in your shade garden in mid-summer, plug some impatient Lucy into the vacant spaces to fill them up again.
The plant has some close relatives that are also in the Arisaema genus, as well as some cousins.
Some of the other types of Arisaema plants are:
- Arisaema consanguineum
- Arisaema saxatile
- Arisaema griffithii
The spathe of A. consanguineum (zones 7 to 9) is purplish with light green stripes, ending in a long "tongue" that makes it look ever so much like a cobra's head. Also with a long tongue is A. saxatile (zones 6 to 9), but in this case, the tongue is the spadix; the spathe is white. The purplish spathe of A. griffithii (zones 7 to 9) is decorated with an elaborate light-green veining pattern at the top.
Arisaema plants are in the arum family. Other members include its neighbor in the woodlands of eastern North America, skunk cabbage (Symplocarpus foetidus), which is also characterized by a hooded structure that covers its flowers. Europe is home to a plant similar to A. triphyllum, called Arum maculatum; the plant even shares with A. triphyllum the common names, "Jack-in-the-pulpit" and "wake robin." Another plant grown for its interesting spathe is the much larger snake lily (Amorphophallus konjac).